1. Field of the Invention
The present invention relates to improvements in a toroidal type continuously variable transmission (CVT), and more particularly to a toroidal transmission having two toroidal cavities around a common axis (often called a dual cavity type).
2. Description of the Prior Art
Hitherto, a variety of toroidal cavity type continuously variable transmission have been proposed. A typical toroidal cavity type continuously variable transmission is disclosed, for example, in Japanese Patent Provisional Publication Nos. 1-206150 and 1-216158, in which a pair of toroidal type continuously variable transmission (CVT) mechanisms are used and a forward-reverse switching device is disposed apart from an engine so as to sandwich the CVT mechanisms with the engine. In particular, Japanese Patent Provisional Publication No. 1-216158 discloses a toroidal type continuously variable transmission (CVT) in which an input shaft is connected to a torque converter and an output shaft is connected to a forward-reverse switching device.
Accordingly, with such a conventional arrangement, when a control valve assembly is disposed around the forward-reverse switching device, the responsibility of the hydraulic pressure from a control valve assembly is degraded due to the extension of oil passages. On the other hand, when the control valve assembly is disposed around the CVT in order to avoid a degradation of the responsibility of the hydraulic pressure, it is difficult to ensure a space for the control valve assembly around the CVT.